constraint flowdown question

Dear friends of semantics,

** A little background

In WAI-ARIA we *are* as of now using @role for things that have
reference explanations that are accessible by QName. And the
'reference explanations' in our present approach are classes in an
OWL ontology. We are not sure about how constraints, e.g.
cardinality, in the ontology affects conformance once an instance
names that class in its @role value.

** Two theories

Here are two ways of understanding how it works:

Theory A:

Owl cardinality constraint can only refer to usages
inside RDF.  I don't think we can legally use it to constrain
the usage of native mark up which it abstracts.

Theory B:

The syntax given in our XHTML 1.1 dialect defines patterns that
match, that specialize the classes in the ontology. (There is, in
principle, a binding that says what patterns in the syntax are
specializations of what patterns in the abstract model.) Instances of
those patterns in a WAI-ARIA-conforming document in that syntax
satisfy the constraints given in the abstract OWL pattern. The use of
one of our role definitions in OWL as the value of @role in an XHTML
1.1-extended document imports the assertions, including constraint
assertions, that are written in the OWL and says they are applicable
to this element instance in the XHTML.

Rationale -- why do we care?

People make interactive widgets by scripting all sorts of syntactic
elements.  WAI-ARIA is a way to live with that.  But an interactive
element where the user can do something requires (for accessiblity)
a label giving a notion of what it does.

In legacy HTML without the scripted behavior, we have guidelines
linking this to the INPUT element.  In XForms, it's enforced by the
specification.   But in the wild west of AJAX, shall we say, we seek
to hang this rule on a Role.

We can't make the population constraint that there has to be an
@aaa:labeledby attribute in the syntax because it cuts across
element types.  But we can say in the role template that something
of this nature has to be there, because it is specific to certain roles.
The question is, is it binding?

Inheritance here, if it works, is transitive:

The grand-specific inherits constraints from the grand-generic and
the grand-generic inherits instances from the grand-specific.

here:
- grand-specific is a class in our ontology
- mid-specific = mid-generic is some pattern in the DOM of the syntax
- grand-specific is a document instance that aspires to conform to
our spec.

We can't just replicate the population
constraints in the DTD because they are cross-attribute of
the form (by example):

WHEN
   attribute @role has value exampleQName
THEN
   attribute @labeledby MUST occur at least once.

** recap

The question is:

Can we, or can't we, constrain instances of our DOCTYPE from
constraints in the OWL that aren't replicated or narrowed in the DTD.

Al

Received on Thursday, 22 February 2007 18:33:00 UTC